Wash and dry produce. 

Drain and rinse beans. Trim and thinly slice scallions; separating whites from greens. Quarter lime. Roughly chop cilantro. 

Transfer beans to a medium microwave-safe bowl. (Rinse out strainer.) Stir in half the chili powder (you’ll use more later), 1 TBSP water (2 TBSP for 4 servings), a drizzle of oil, a pinch of salt, and pepper. Cover with plastic wrap and microwave until warmed through, 1-2 minutes.

Add a squeeze of lime juice; stir to combine.

Drain corn; pat dry with paper towels. 

Heat a drizzle of oil in a large pan over high heat. Add corn and scallion whites; cook, stirring occasionally, until golden brown and lightly charred in spots, 4-6 minutes. TIP: Cover pan if corn begins to pop!

Meanwhile, in a large bowl, combine mayonnaise, half the cotija, remaining chili powder (use less chili powder if you prefer less heat!), juice from two lime wedges (four wedges for 4 servings), a big pinch of salt, and pepper. 

Once corn is done, turn off heat. Transfer to bowl with mayonnaise mixture; stir to thoroughly combine. Taste and season with salt and pepper if desired. Set aside until ready to serve. Wash out pan.

Place tortillas on a clean work surface. Evenly divide beans, Mexican cheese blend, and remaining cotija between bottom halves of tortillas. Fold in half to form quesadillas. 

Heat a drizzle of oil in pan used for corn over medium heat. Add quesadillas; cook until tortillas are golden brown and cheese melts, 2-4 minutes per side (work in batches if needed and lower heat if tortillas begin to brown too quickly).

Cut quesadillas into wedges; divide between plates and dollop with sour cream. Serve esquites on the side. Squeeze juice from remaining lime over esquites. Sprinkle everything with scallion greens and cilantro. Serve.